In wireless communication, and particularly in broadband transmission, in addition to a first reception path, there are paths that arrive with a delay, by reflections from obstacles such as buildings and mountains, thereby resulting in intersymbol interference (ISI). An environment such as this having a plurality of paths of arrival is known as a multipath environment. For example, in multicarrier transmission, such as in OFDM (orthogonal frequency division multiplexing), OFDMA (orthogonal frequency division multiple access), and MC-CDM (multicarrier code division multiplexing), a guard interval (GI) is added to the multicarrier time-domain signal so as to prevent ISI, as long as the delay path is within the GI. Therefore, if the GI length is properly set, it is possible to achieve good transmission quality that is not affected by ISI. However, in the case in which the reception device is moving at a high speed, the propagation channel variation within one OFDM symbol becomes large, resulting in the occurrence of intercarrier interference (ICI). Such an environment is known as high-speed fading. ICI greatly deteriorates the receiving performance.
Non-Patent Reference 1 describes turbo ICI cancellation technology. Specifically, Non-Patent Reference 1 describes the generation of an ICI replica from the bit-log likelihood ratio (LLR) of the results of error correction decoding and the removal of the generated replica from the received signal, so as to suppress the ICI and perform suppression of the ICI removal residue and optimum detection with respect to the signal remaining after the removal.